Border staff are among government workers who are set to strike on the eve of the Olympics, union leaders announced Thursday, risking longer lines at Heathrow airport's passport control for visitors arriving for the Games.

The Public and Commercial Services union called the strike for its members across the home office for July 26, a day before the Olympic Games open.

This could also have an impact on the authorities' capacity to process the huge numbers of people expected to arrive in the United Kingdom for the Olympics, which end on August 12, and the Paralympic Games two weeks later.

Immigration minister Damian Green condemned what he called "a completely selfish and irresponsible decision by a small minority of union members."

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He said union leaders had been wrong to call their members out on strike and predicted the British public would have little sympathy for those taking action.

"In little more than a week's time, the eyes of the world will be on Britain, with soldiers and police officers canceling their leave and working extra hours to make the Olympics a success. The PCS leadership should be ashamed of themselves," he said.

The action includes staff across the home office, including the UK Border Agency, the Identity and Passport Service and Criminal Records Bureau, the union said.

PCS general secretary Mark Serwotka said: "The lives of staff have been made intolerable by these cuts, and they're at breaking point. Ministers have known about these issues for a very long time and need to act now to sort out the chaos they have caused. They're acting recklessly in cutting so many jobs and privatizing services, and are provocatively refusing to talk to us with a genuine desire to reach an agreement."

Concerns had already been raised about how Heathrow and other entry points to the United Kingdom would cope with the influx of Olympic visitors even before the threat of strike by some staff.

Heathrow said Monday that extra staffers have been posted on immigration desks amid fears of long lines to get into the country as security checks are carried out.

Retired border officials and retired police officers are among those being brought in to supplement immigration staff, the home office said.